1. Field of the Invention
The present invention relates to a non oil coated construction form, and more particularly, to a form which is made of braided hemp fiber impregnated in phenolic resin and hardened by a hardener, and after the steps of drying, cooling, cutting and thermocompressing to be formed into a laminated phenolic compound resin material with intensified mechanical strength and a smooth surface. The life time of the construction form made as such is more than five times that of a conventional water proof form, and furthermore, convenient to handle in working site.
2. Brief Description of the Prior Art
At present, most of constructional works are built of steel reinforced concrete. In the construction work, a plurality of lumber plates with struts are used to form a cavity of steel bars in a certain configuration wherein wet concrete is deposited. After the concrete has dried, the lumber form is detached and there appears a constructional body of concrete block. However, a form plays an important role in construction work.
FIG. 1A shows a typical conventional lumber form 1 which is composed of a plurality of lumber plates cut from a whole piece of lumber. A unit of lumber form includes a pair of upright struts 2, 3 with a plurality of transversely laid lumber plates 4, 5, 6 . . . therebetween and connected with nails. A cavity of construction body is surrounded by the form 1 which is composed of these successively laid plurality of transverse plates 4, 5, 6 . . . thereby ready for depositing wet concrete.
Incidentally, there are some shortcomings inherent to such conventional techniques, and are as follows:
1. The grains and streaks of wood on the unbuffed surface of the lumber plates 4, 5, 6 . . . may be printed on the surface of the concrete body requiring an additional step of removing them by polishing after detaching the form. PA1 2. Moreover, a poor rugged surface of the concrete body will result by the burrs existing on the surface of the lumber plates 4, 5, 6 . . . , especially in the case when rapid drying cement is used. Both the form and the surface of the concrete body will be damaged. PA1 3. The wet concrete may leak through the clearances 1A, 1B . . . formed between adjacent plates 4, 5, 6 . . . during concrete deposition which causes not only wasting the concrete and contaminating the work site, but also obtaining a concrete body with rugged ugly surface. PA1 4. For the purpose of eliminating the above mentioned shortcomings, in the recent construction site of a chemical work located at the west sea coast of middle Taiwan, oil was applied to coat on the surfaces of the plates 4, 5, 6 . . . which were in contact with the concrete. But there happened an unexpected event that sand particles brought by sea winds stick to the surface of undried oilly surface of the concrete body whereby resulting in a concrete body with an ugly scarred surface since it took time to wait for oil to dry up.
FIG. 1B shows another type of a conventional form made of steel. The steel form 10 with smooth surface has the advantages of easily detachable after concrete dries, the smoothly finished concrete surface can be obtained without the necessity of successive step of polishing the concrete surface to follow. On the other hand, the price of the steel form 10 is disadvantageously too expensive.
In order to overcome the disadvantages inherent to the conventional lumber form, the inventor of the present invention disclosed by the title of "Manufacturing Method for Construction Form Material Composed of Hemp Fiber" (Application No. 83104062) which was honored by a patent from Patent Bureau of Taiwan. From then on, he has continued to do his best for research and experiment trying to discover more perfect and innovative product in this field and fortunately succeeded in providing non oil coated construction form of the present invention which is now to be disclosed hereinafter.